ARLINGTON, VA – JANUARY 27: U.S. President Donald Trump signs executive orders in the Hall of Heroes at the Department of Defense on January 27, 2017 in Arlington, Virginia. His administration on Tuesday will defend his executive order on immigration. (Photo by Olivier Douliery-Pool/Getty Images)

SAN FRANCISCO — Federal appellate judges grilled the lawyer defending President Donald Trump’s immigration ban Tuesday, demanding answers to tough questions in a case that marks the biggest legal challenge the president’s new administration has faced.

As thousands of people tuned in to listen to the live-streamed proceedings, three judges questioned whether there was evidence that proved immigrants barred from the U.S. under Trump’s order posed a security threat — and seemed unconvinced by the administration’s responses.

The panel also peppered the lawyer challenging the immigration ban with questions, tearing down his argument that the executive order constituted an attack against Muslims.

The unusual, hourlong telephone hearing before the Ninth Circuit Court of Appeals addressed whether Trump’s order temporarily blocking immigrants from Iraq, Iran, Libya, Somalia, Sudan, Syria and Yemen should remain suspended following a Seattle judge’s ruling. Tuesday’s arguments raised loftyquestions regarding the limits of presidential power, highlighting the far-reaching implications the Ninth Circuit’s ruling will have not just for immigrants, but for Trump’s presidency as a whole.

A decision in the case — which has captivated Silicon Valley and the nation — could come as early as Wednesday. Any ruling by the panel is expected to be appealed to the U.S. Supreme Court.

The judges spent significant time addressing how much power the president has, and who is able to question his authority. The immigration order’s challenger, Washington State Solicitor General Noah Purcell, said it is the court’s job to check the president.

“It has always been the judicial branch’s role to say what the law is and to serve as a check on abuses by the executive branch,” he said. “That judicial role has never been more important in recent memory than it is today. But the president is asking the court to abdicate that role here, to reinstate the executive order without meaningful judicial review and to throw this country back into chaos.”

August Flentje, special counsel to the assistant U.S. attorney general, countered that the president has sweeping power to control the flow of immigrants into the country, and individual states have no standing to challenge that control in court.

“It is extraordinary for a court to enjoin the president’s national security determination based on some newspaper articles,” he said, “and that’s what has happened here. That is very troubling second guessing of the national security decision made by the president.”

Flentje said Trump suspended immigration from the seven countries listed in the executive order because those countries already had been determined by Congress and the previous administration to pose threats of terrorism.

“I understand the concept of that, but it’s pretty abstract,” Senior Circuit Judge Richard Clifton said, “and it’s not like there haven’t been processes in place to take some care with people coming from those countries.”

When pressed, Flentje said a number of people from Somalia with ties to a militant group have been arrested and convicted in the U.S., but when Circuit Judge Michelle Friedland asked if that evidence had been submitted to the court, Flentje said no.

The judges also were tough on Purcell.

Clifton didn’t buy Purcell’s argument that the ban discriminated against Muslims. The seven countries covered in the ban account for a small percentage of the world’s Muslims, he said.

Purcell cited inflammatory statements Trump made in public about immigration, such as calling for a complete ban on Muslims during his campaign. Those soundbites show a “shocking intent” to discriminate, which should be taken into account when reviewing his immigration order, Purcell said.

Purcell also addressed the human side of the issue, telling the judges that life is slowly returning to normal in Washington since the immigration order was suspended.

“We had students and faculty at our state universities that were stranded overseas,” he said. “We had families that were separated.”

The judges’ tough questions during the hearing sometimes had Flentje fumbling, and he suggested his team hadn’t submitted certain evidence backing up Trump’s immigration ban because the case was moving so fast. At one time he admitted: “I’m not sure that I’m convincing the court.”

Purcell also cited the fast-moving nature of the case when pressed by the judges for evidence it appeared he hadn’t prepared. Clifton was no easier on him, saying the court had heard too many allegations and not enough evidence.

“I don’t think allegations cut it at this stage,” he said.

Flentje also appeared to back off his prior argument slightly midway through the hearing. Even if the judges have problems with the immigration ban, he said, they should consider limiting the order suspending the ban so that only long-term U.S. residents are allowed back into the country. Foreigners with no ties to the U.S. and who have never set foot in the country should not be protected by the court’s order, he said.

Ben Feuer, chairman of the California Appellate Law Group, which is not involved in the case, said after hearing the arguments that it seemed the judges had not made up their minds.

“I think that the panel is clearly wrestling with the many complicated issues that are presented,” he said, “by both this appeal and the particular procedural posture of the appeal and how it’s coming to the court.”

Marisa Kendall covers housing for the Bay Area News Group, focusing on the impact local companies have on housing availability in the region. She's also written about technology startups and venture capital for BANG, and covered courts for The Recorder in San Francisco. She started her career as a crime reporter for The News-Press in Southwest Florida.

According to the federal charges, Russian operatives spread pro-Trump and anti-Clinton propaganda. They posed as Americans to coordinate and infiltrate political activities. They organized grass roots rallies. They paid for a cage large enough to hold an actress impersonating Clinton in a prison uniform.

The indictment shows a concerted years-long effort by a group dedicated to undermining the American political system. It shows the scale of that effort, eventually involving 80 staff in St. Petersburg, a budget of more than a million dollars a month, hundreds of social media accounts, stolen identities of American citizens – and even visits into the United States by...